[core] Render fill-extrusion layers (#8431)

1 files changed, 81 insertions, 0 deletions

diff --git a/src/mbgl/programs/fill_extrusion_program.cpp b/src/mbgl/programs/fill_extrusion_program.cpp
new file mode 100644
index 0000000000..67426c8d9d
--- /dev/null
+++ b/src/mbgl/programs/fill_extrusion_program.cpp
@@ -0,0 +1,81 @@
+#include <mbgl/programs/fill_extrusion_program.hpp>
+#include <mbgl/sprite/sprite_atlas.hpp>
+#include <mbgl/style/cross_faded_property_evaluator.hpp>
+#include <mbgl/tile/tile_id.hpp>
+#include <mbgl/map/transform_state.hpp>
+#include <mbgl/util/mat3.hpp>
+
+namespace mbgl {
+
+using namespace style;
+
+static_assert(sizeof(FillExtrusionLayoutVertex) == 12, "expected FillExtrusionLayoutVertex size");
+
+std::array<float, 3> lightColor(const EvaluatedLight& light) {
+    const auto color = light.get<LightColor>();
+    return {{ color.r, color.g, color.b }};
+}
+
+std::array<float, 3> lightPosition(const EvaluatedLight& light, const TransformState& state) {
+    auto lightPos = light.get<LightPosition>().getCartesian();
+    mat3 lightMat;
+    matrix::identity(lightMat);
+    if (light.get<LightAnchor>() == LightAnchorType::Viewport) {
+        matrix::rotate(lightMat, lightMat, -state.getAngle());
+    }
+    matrix::transformMat3f(lightPos, lightPos, lightMat);
+    return lightPos;
+}
+
+float lightIntensity(const EvaluatedLight& light) {
+    return light.get<LightIntensity>();
+}
+
+FillExtrusionUniforms::Values
+FillExtrusionUniforms::values(mat4 matrix,
+                              const TransformState& state,
+                              const EvaluatedLight& light) {
+    return FillExtrusionUniforms::Values{
+        uniforms::u_matrix::Value{ matrix },
+        uniforms::u_lightcolor::Value{ lightColor(light) },
+        uniforms::u_lightpos::Value{ lightPosition(light, state) },
+        uniforms::u_lightintensity::Value{ lightIntensity(light) }
+    };
+}
+
+FillExtrusionPatternUniforms::Values
+FillExtrusionPatternUniforms::values(mat4 matrix,
+                                     const SpriteAtlasElement& a,
+                                     const SpriteAtlasElement& b,
+                                     const Faded<std::string>& fading,
+                                     const UnwrappedTileID& tileID,
+                                     const TransformState& state,
+                                     const float heightFactor,
+                                     const EvaluatedLight& light) {
+    int32_t tileSizeAtNearestZoom = util::tileSize * state.zoomScale(state.getIntegerZoom() - tileID.canonical.z);
+    int32_t pixelX = tileSizeAtNearestZoom * (tileID.canonical.x + tileID.wrap * state.zoomScale(tileID.canonical.z));
+    int32_t pixelY = tileSizeAtNearestZoom * tileID.canonical.y;
+
+    return FillExtrusionPatternUniforms::Values{
+        uniforms::u_matrix::Value{ matrix },
+        uniforms::u_pattern_tl_a::Value{ a.tl },
+        uniforms::u_pattern_br_a::Value{ a.br },
+        uniforms::u_pattern_tl_b::Value{ b.tl },
+        uniforms::u_pattern_br_b::Value{ b.br },
+        uniforms::u_pattern_size_a::Value{ a.size },
+        uniforms::u_pattern_size_b::Value{ b.size },
+        uniforms::u_scale_a::Value{ fading.fromScale },
+        uniforms::u_scale_b::Value{ fading.toScale },
+        uniforms::u_mix::Value{ fading.t },
+        uniforms::u_image::Value{ 0 },
+        uniforms::u_pixel_coord_upper::Value{ std::array<float, 2>{{ float(pixelX >> 16), float(pixelY >> 16) }} },
+        uniforms::u_pixel_coord_lower::Value{ std::array<float, 2>{{ float(pixelX & 0xFFFF), float(pixelY & 0xFFFF) }} },
+        uniforms::u_tile_units_to_pixels::Value{ 1.0f / tileID.pixelsToTileUnits(1.0f, state.getIntegerZoom()) },
+        uniforms::u_height_factor::Value{ heightFactor },
+        uniforms::u_lightcolor::Value{ lightColor(light) },
+        uniforms::u_lightpos::Value{ lightPosition(light, state) },
+        uniforms::u_lightintensity::Value{ lightIntensity(light) },
+    };
+}
+
+} // namespace mbgl